Grain bags, typically made from plastic, are becoming popular for storing grain including corn, beans, wheat, and like agricultural products. The bags are attached to a loading machine which receives grain from a transport vehicle, and pushes the grain into the bag. As the bag fills, the machine moves ahead, such that the grain bag fills and stretches out behind the loading machine. A typical bag will be about ten to twelve feet across, and 200 or more feet long.
To unload the bag, an extractor machine is provided that includes feed augers extending laterally right and left along the ground from the input end of an upright oriented main auger. The main auger has an elevated discharge oriented to discharge into a transport vehicle.
Thus to unload a bag, the end of the bag is cut open and the feed augers moved into the bag. The machine moves forward as the grain is collected by the feed augers and raised to the transport vehicle by the main auger. A knife at the top rear of the machine is oriented to slice the top of the bag as the machine moves forward as the grain is removed.
In a typical machine the empty bag is taken up on a pinch roller so that grain left on the bag spills rearward and into the bag and is thus saved. Such grain bag extractors are disclosed for example in U.S. Pat. Nos. 7,861,851 and 8,336,704 to the present inventor Dekoning, U.S. Pat. No. 7,997,849 to Twiestmeyer, et al., and U.S. Pat. No. 8,251,630 to Hilsabeck et al.
These grain storage bags have become popular since the cost is only a few cents per bushel, and the bags can be filled in the field where the crop is grown, reducing the need for trucks to haul grain from the combine to distant storage facilities. Also it has been found that the plastic bags reduce or prevent air movement through the grain and so grain can be stored at a higher moisture content without spoiling than is possible in conventional storage.